1. Field of the Invention
The present invention relates to a clock-synchronous semiconductor memory device and access method thereof which operates synchronously with a basic clock signal, and, in particular, to a clock-synchronous semiconductor memory device and access method thereof in which an address for accessing can be set synchronously with a basic clock signal, and a clock-synchronous semiconductor memory device and access method thereof in which an address for accessing can be set when a high-frequency basic clock signal is used.
2. Description of the Prior Art
The inventors of the present invention have previously proposed a basic method for controlling a memory operation for a semiconductor memory device synchronized with a basic clock signal (Japan Application No. 3-255354).
At that time, several methods were illustrated for controlling a memory access by means of an external control signal, but nothing was disclosed as to how to set a external control signals synchronously with a basic clock signal and with respect to setting specific timing for an address signal or the like for the external control signals.
Moreover, there is a problem that it is difficult to access data when a high-frequency basic clock signal is used in a conventional a clock-synchronous semiconductor memory device and access method thereof.